77 k10 with 86 350

[perhamite]

Hello everyone, I'm new but not new to wrenching. First post was my intro post. I bought a 77 k10 shortbed custom deluxe with an 86 350 swapped in. It has the sm465 Muncie 4spd and np205  transfer. I bought it because it wouldn't go in gear and needed a clutch. I pulled it apart and put a new 12" clutch kit ,( I believe it's the correct one for this 1986 168 tooth flywheel) with pressure plate, pilot bearing, friction disc, and throw out bearing. I machined the flywheel and replaced the clutch fork.  It is the 77 clutch fork and an 86 clutch kit with the 77 tranny. Well after 2 months of driving the clutch won't engage again and I have to pull it all back apart. Looks like the throw out bearing, which is new. Is there a mismatch here that I need to correct?

[Captkaos]

Well the trans input change at sometime so "technically" the clutch could not fit.  So explain what you mean by 86 clutch kit?  85-up used a hydraulic throw out also...

Chris Lucas
73-87chevytrucks.com
squarebody.biz

[perhamite]

The engine and flywheel are from an 86 k10, or so I was told. The engine does have a 1 piece rear main seal but the valve covers do not have center bolts. So I bought a clutch for the 86 flywheel  (clutch disc, pressure plate, throw out bearing) the transmission, bell housing, and cutch fork are original 1977. Do i need  a 77 clutch kit? Will it fit to the 168 tooth flywheel? Everything has been working for nearly 2 months till the throwout bearing self destructed.
 thank you for your help

[bd]

Does the T/O bearing fit the front bearing retainer w/o rocking?  Was there any noise leading up to the failure?  Are you sure the T/O bearing is releasing completely and pulling free from the clutch?  Did the bearing burn up and grenade?

[perhamite]

The T/O bearing fit the clutch fork retainer well. There was no noise leading to the failure. I am not sure the bearing was releasing completely. I will be pulling the tranny back soon and report on what I see. So far the clutch fork is no longer centered in the bell housing hole and I can move it around. It is making a lot of noise and the clutch pedal is vibrating and it won't go into gear.

[bd]

While your in there checking it out make a thorough inspection of the pivot ball and the attachment of the fork to the ball.

[perhamite]

Will do, thanks for the help

[perhamite]

Well the update, this is my sons first truck and we pulled it apart together. We found that the new throwout bearing was toast. I checked the bellhousing and made sure it was flat and square, it was. Checked the release fork arm and ball stud, both at spec. Checked the crank centerline against the bellhousing and it was centered. Put it all back together with new parts and found that the throwout bearing was not completely releasing. We adjusted that for an 1/8" of release distance so we knew it wasn't dragging. It is working great now. I found out in the process that the 86 clutch and the 77 clutch are the same, even have the same part number. Only difference is that the 77 is not hydraulic but that didn't make a difference once I got it set up correctly. We put all new gaskets and seals in the trans and transfer and put it all back together. Thanks for the help.